Fitted Mattress Cover with Integrated Sensor Elements for Monitoring the Presence of a Person on a Mattress

ABSTRACT

A bedding system component that provides for the incorporation of sensor elements into a fitted mattress cover for the detection of dielectric shift induced capacitance changes for the monitoring of the presence or absence of a person in a medical bed. The mattress cover is preferably fitted so as to be securely retained over and around the standard sized hospital patient beds. A variety of sizes are anticipated. The sensor elements are unobtrusively placed on the underside of the mattress cover and are provided with conductive snap connectors for connection to one or more of the patient monitoring systems described in the references cited above. The sensors are preferably configured using conductive ink and may be printed onto the underside surface of the fabric mattress cover. The fabric of the cover is preferably Tyvek® material or another inexpensive (disposable) material with similar strength and water resistant characteristics. An alternate embodiment of the present invention includes an array of perforations on the top surface to permit use of the cover on low air loss mattresses.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under Title 35 United States Code §119(e) of U.S. Provisional Application No. 61/316,316; Filed: Mar. 22, 2010, the full disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to sensors for the detection of dialectric shift induced capacitance changes. The preset invention also relates generally to fitted mattress covers. The present invention relates more specifically to the incorporation of sensor elements into a mattress cover for the detection of dielectric shift induced capacitance changes for the monitoring of the presence or absence of a person in a medical bed.

2. Description of the Related Art

The present invention is intended to be utilized in conjunction with a variety of patient monitoring systems of the types described in the disclosures of the following U.S. Patents, the disclosures of which are each incorporated herein in their entirety by reference:

U.S. Pat. No.: 6,778,090; Issued: Aug. 17, 2004; Entitled: Modular System for Monitoring the Presence of a Person Using a Variety of Sensing Devices;

U.S. Pat. No.: 6,307,168; Issued: Oct. 23, 2001; Entitled: Linear Spaced Dielectric Dot Separator Pressure Sensing Array Incorporating Strain Release Stabilized Releasable Electric Snap Stud Connectors;

U.S. Pat. No.: 6,297,738; Issued: Oct. 2, 2001; Entitled: Modular System for Monitoring the Presence of a Person Using a Variety of Sensing Devices; and

U.S. Pat. No.: 6,025,782; Issued: Feb. 15, 2000; Entitled: Device for Monitoring the Presence of a Person Using Proximity Induced Dielectric Shift Sensing.

SUMMARY OF THE INVENTION

The present invention provides for the incorporation of sensor elements into a fitted mattress cover for the detection of dielectric shift induced capacitance changes for the monitoring of the presence or absence of a person in a medical bed. The mattress cover is preferably fitted so as to be securely retained over and around the standard sized hospital patient beds. A variety of sizes are anticipated. The sensor elements are unobtrusively placed on the underside of the mattress cover and are provided with conductive snap connectors for connection to one or more of the patient monitoring systems described in the references cited above. The sensors are preferably configured using conductive ink and may be printed onto the underside surface of the fabric mattress cover. The fabric of the cover is preferably Tyvek® material or another inexpensive (disposable) material with similar strength and water resistant characteristics. An alternate embodiment of the present invention includes an array of perforations on the top surface to permit use of the cover on low air loss mattresses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the fitted mattress cover of the present invention seen from the exterior with the sensor elements shown on the interior surface of the cover material in dashed line form.

FIG. 2 is a perspective view of the fitted mattress cover of the present invention, inverted from the orientation shown in FIG. 1, showing the interior surface of the cover material.

FIG. 3 is a cross sectional view of the side panel and part of the top panel of the mattress cover of the present invention.

FIG. 4 is a detailed side elevational view of a portion of the side panel of the mattress cover of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a fitted mattress cover made of a germicidal impregnated fabric (preferably Tyvek®) material 5 mil-8 mil thick (1 mil=0.001 inch). The fully fitted disposable mattress coverlet is manufactured from appropriate sized sheets of Tyvek® non-woven fabric or a similar type of fabric material having equivalent or similar strength and porosity properties. The coverlet fabric of the present invention is impregnated with a non-leaching germicidal agent such as the Dow Chemical product DC-Q9-5700 hypo-allergenic treatment.

The sensor elements of the present invention are electrically structured to be appropriate for use in conjunction with the proximity fall-prevention sensors and sensor systems as described in the above referenced issued U.S. Patents. The sensor elements are preferably printed on the underside of the fitted mattress cover in at least one location (and preferably two parallel locations) and are provided with connector studs or snap connectors on (or through) the sidewalls of the mattress cover.

FIG. 1 shows an external view of the fitted mattress cover 10 having a planer top surface 12 configured with sidewalls 14 designed to surround, cover, and remain secure on a typical hospital mattress. The corners of mattress cover 10 are each gathered with elastic material 16 as is known in the art. The bottom perimeter edge of the fitted mattress cover 10 may also incorporate an elastic band 18 to further secure the mattress cover to the mattress (not shown).

Sensor elements 20 a & 20 b are incorporated on the inside (underside) surface of the fabric material of the mattress cover 10 in a manner described in more detail below. Connector studs 22 a & 22 b are positioned on each of the longer sidewalls where sensor elements 20 a & 20 b meet the sidewalls 14.

FIG. 2 is an inverted view of the mattress cover shown in FIG. 1 wherein the sensor elements are more clearly seen and the manner in which they are placed and positioned on the inside (underside) surfaces of mattress cover 10 are shown. In this view, sensor elements 20 a & 20 b are seen to comprise conductive carbon ink proximity sensor material 24 a & 24 b printed on the underside of the fitted mattress cover 10. Again, the electrically conductive connecting studs 22 a & 22 b for connection of the appropriate instrumentation for utilizing the sensor elements are likewise seen in this view. The connecting studs 22 a & 22 b extend through the mattress cover material to make electrical contact with the conductive ink on the interior and to provide snap connector contacts on the exterior of the cover.

FIG. 3 shows a cross sectional view of the side panel and part of the top panel of the mattress cover of the present invention. As described above, the fitted mattress cover includes a planer top surface 12 configured with sidewalls 14 which are joined at hem 13 to form a fitted edge to the cover. The bottom perimeter edge 17 of the fitted mattress cover 10 may also incorporate an elastic band 15 to further secure the mattress cover to the mattress (not shown). The sensor elements are incorporated on the inside (underside) surface of the fabric material of the mattress cover by placement of the conductive carbon ink proximity sensor material 24 printed on the underside of the top panel 12 and the inside surface of side panel 14. Connector stud 22 is shown positioned on sidewall where the sensor element (comprising conductive ink surface 24) meets the sidewall 14.

FIG. 4 is a detailed side elevational view of a portion of the side panel of the mattress cover of the present invention. Once again, the fitted mattress cover includes a planer top surface configured with sidewalls 14 which are joined at hem 13 to form a fitted edge to the cover. The bottom perimeter edge 17 of the fitted mattress cover 10 may also incorporate an elastic band 15. The sensor elements are incorporated on the inside (underside) surface of the fabric material of the mattress cover by placement of the conductive carbon ink proximity sensor material 24 a & 24 b shown printed on the inside surface of sidewall 14 in the view of FIG. 4. Connector studs 22 a & 22 b are shown positioned through sidewall 14 where the sensor elements (comprising conductive ink surfaces 24 a & 24 b) meet sidewall 14.

The fitted mattress cover of the present invention may preferably utilize a germicidal, hypo-allergenic, material that incorporates fall prevention sensor elements for use in conjunction with the above referenced patient monitoring and sensing systems.

An alternate embodiment of the present invention may be used in conjunction with low air loss surface mattresses and includes an array of perforation apertures on all surfaces that come in contact with the low air loss mattress surfaces. This perforation array will preferably include 1 mm diameter perforations spaced approximately 5 mm apart (radially from each other) across the entire sleep surface component (12 in FIG. 1) that will allow continued air flow to occur. To retain the maximum fabric tensile strength, the coverlet skirt (the sidewalls) would preferably not be perforated. The perforations on the sleep surface component of the mattress cover could extend through the sensor element areas of the sleep surface without significantly altering the functionality of the sensor elements.

In the manner described above, the present invention provides an easily manufactured mattress coverlet made of relatively inexpensive fabric material so as to be disposable (if desirable) after use in conjunction with a given patient. The mattress cover provides the necessary conductive elements to function as sensor elements in a patient monitoring system and yet still remains pliable enough to maintain the comfort of the patient on the mattress surface. The use of Tyvek® fabric or a similar type of fabric material retains the necessary tensile strength to the fabric to prevent significant deformation of the sensor elements and thus to reduce any significant alteration of their electrical characteristics.

Although the present invention has been described in terms of the foregoing preferred embodiments, this description has been provided by way of explanation only, and is not intended to be construed as a limitation of the invention. Those skilled in the art will recognize modifications of the present invention that might accommodate specific patient sensing sensor elements and/or specific system control unit modules. Such modifications, as to conductivity, electrical characteristics, connector structure, conductive ink compositions and methods of application, and even sensor configurations, where such modifications are coincidental to the type of mattresses and control units being utilized, do not necessarily depart from the spirit and scope of the invention. 

1. A bedding system component comprising a fitted mattress cover for placement over a bed sized mattress support surface, the mattress cover comprising: a top panel sized and shaped to generally cover the support surface of the bed sized mattress, the top panel comprising a sheet of flashspun high-density polyethylene fibers; a plurality of elastic members attached to the top panel for securing the top panel to the support surface of the bed sized mattress; first and second sensor elements extending in a spaced relationship to each other at least partially across the top panel, the sensor elements each comprising printed areas of conductive ink deposited on a surface of the top panel; and first and second electrical connectors, each connector electrically engaging one of the first or second sensor elements; wherein connection of the electrical connectors to a patient monitoring system allows the mattress cover to function as a sensor for the detection of dielectric shift induced capacitance changes for the monitoring of the presence or absence of a person. 